Disc plows

Just browsing through the latest ASC flyer got me thinking about disk plows (again).
Anyone build one for say a 30, 40 or 50 HP tractor from the 24 & up inch disks ?
Any Guestimates what sort of size and how many disks a 30/40/50 HP tractor could reasonably pull ?
I guess you could just go shallow or narrow angle if you overbuilt - or have an excuse to upsize the tractor...

Oh yeah, I want it ALL - reversible would be nice and since it would probably have to be adjustable for angle that pivot axis would be needed anyway.

Thoughts ?

BTW, are disk plows a "Bad Idea" due to the sort of scalloping cuts they make ?
They don't cut a flat bottom like a mold board plow, does this matter ?

Re: Disc plows

Since there are a lot of variables such as diameter, spacing, quantity of blades and set angle I would consult the spec sheets of available disks to get an idea. In other words if you see an eight ft disc with the blades and spacing you want and needs 80 hp to pull it then a your using about 10 hp per ft of width. Just transpose the numbers to get the info you want.

Disk plows are not a bad idea, if you are making multiple passes the ridges should be cancelled out.

Re: Disc plows

Which kind of unit... a plowing disk is sometimes called a disk plow. If that is what you are talking about 6 foot is all that hp will handle and that is pulling it.

If you mean the older one way disk plows with larger blades of 24" or more, then you are talking about the same disks as the tractor is rated to plow with a moldboard. My dad had an old disk plow for an H and it was great in sprouts back in the day.

Re: Disc plows

Agreed, but most of those spec sheets are based on disc HARROWs used to break up clods of already ploughed (broken) soil.
I was asking about disc PLOWS (ploughs) as primary ground breaking tools.
Since my original post I have done a few searches, this table;Krause Corporation - Press Release
shows class III as primary tillage, so right now I'm thinking that I would be shopping for 2 (or 3) 24 or 26 inch disks each weighing somewhere around 250 lbs.
I know, that is the upper end of the range suggested for HARROWS, but this would be for use as a PLOW.
Obviously I would need to do the arithmetic on 3PH capacity, those 250 lb weights would be "hanging out and back a way" - plus frame weight.

Anyway, just asking around to see if anyone else had done all this.
I am also looking here;Disc Plough, Ox Plough.
and at tuffline for "ready made",
Plus the used market; for <$500 I could probably get all set up, certainly for <$1,000.

Re: Disc plows

I know you said you wanted to build your own, but did a quick search on Tractorhouse, and found this... A Dearborn 2 disc, disc plow... Looks decent, and for $375.00. Not reversable, but for the time building, and money on materials..., would this one work..??

Re: Disc plows

Seen an old disc plow today discs measured 30 inches with a coulter on the rear second disc. This thing is massive, in the 600# range. I know my little 30 hp tractor would have an interesting time making it work.

Re: Disc plows

Reg:

As a youngster in the 1950's we pulled two disk John Deere disk plows in Georgia clay with a 420 John Deere that had (I think) about 26-28 serious horsepower. And we pulled a five disk tiller (similar to the plow) with a John Deere A of about 60 serious hp. By serious I mean the radiator, clutch, transmission, etc. were able to handle all day (and some time all night) full throttle plowing in second gear that would stall the tractor in the hard spots unless the plow was raised a bit. If I recall the disk plows pulled a bit easier than the same size turning plow (moldboard), but not much. I expect 12-15hp per disk is needed to turn most soil at a decent speed.

Making one would require obtaining the massive "Lazy Susan" type bearings necessary to withstand the axial load from the soil. The new ones I see for small tractors seem to have very small diameter bearings. The old plows had bearings perhaps 8" in diameter, producing a moment arm say 1/4 the diameter of the disk. These new ones appear to have bearings 1/8 or 1/10 the diameter of the disk. I have not examined them closely, but they don't appear to be nearly as capable as the old ones. The plows we used probably had several thousand hours of use and the original bearings still help up.

I agree with DJ54; if you can find a used one it will be simpler and cheaper. But if you build one, keep us posted.

Re: Disc plows

I recently saw a Dearborn Disc plow that looked to be the front section of a disc but it was purpose built for a single pass plow. I have an old part of an old Oliver I think that was a 3 or 4 bottom that someone cut down to a 2 bottom. They screwed up the 3pt and its kinda cobbled and even rough on our 4000 Ford at work. Im thinking about making a mid mount disc breaker for my Cub out of one disk and bearing and then use the other one for the cutting wheel on my terracing machine Im building. Im posting a picture of the one waydisc plow Id like to find a large gang off a big tandem disk to make one.

Re: Disc plows

Originally Posted by DJ54

I know you said you wanted to build your own, but did a quick search on Tractorhouse, and found this... A Dearborn 2 disc, disc plow... Looks decent, and for $375.00. Not reversable, but for the time building, and money on materials..., would this one work..??

Not sure where you are located, but bet the would palletize it, and you can find the cheapest deal online for shipping...

Thanks,
I know that buying something like that would probably be the simplest way to go.
The design is done, field tested and proven, etc., for not a whole lot of money.

I was just asking (in the Build-It Yourself forum) if anyone had built one, say from the large harrow discs listed by ASC for under ~$50 a piece.

Farmerford,
That is an interesting observation on bearing sizes.
I don't know what to think about changes in materials and bearing technologies in 50 years.
I do expect a single pass breaking plow to experience significantly higher side loads than a disc harrow, which is typically busting clods and finding rocks that have already been loosened.
S'pose I should say that I will be BEARING that in mind ?